The Curse of Oak Island

I like both possibilities, but what if it was an attempt to keep something down there?
Que spooky music.

[Pollux]

There is apparently indications from scanning, and geological surveys on Oak Island - and on nearby islands, and on mainland near Oak Island - that there is natural limestone cave-systems occurring in this area. 

I wonder; could it be that these tunnels on the Oak Island are natural caves that had many natural surface-openings on the island. A cave system that some people discovered way back when landing on this island, and saw the potential to use it as a perfect hiding place for whatever treasure they wanted safe - and that after they placed their treasure down there, they used the soil from the place where the swamp now is, to fill up the natural cave-openings on the island. Then they jsut flooded the new "swamp" (which is close to the shore) and none would be the wiser, that there ever was a natural cave-system there.

They said earlier that they had strong indications that the swamp on the island was man made. It looks rather unnatural, and while searching the swamp a few seasons ago they found an actual long crafted ship-plank from a big sail ship, submerged in the swamp that was dated to be between from the year 1680-1735 with a 95% degree of accuracy. In the swamp was also a ship’s spar and a ship’s scuppers found - (not dated though). They also found a big square-headed nail/spike in the swamp, believed to be a ship's-nail from the way it was formed.

And they also found large oak tree-stumps in the swamp - submerged. Indicating that the swamp area hasn't always been a swamp but actually dry land once, since oaks like that doesn't grow under water. Which brings credence to the theory that the swamp was man-made, and that large quantities of soil must have been removed to create that swamp.

That would solve the mystery why this swamp was created - and where the large amount of soil, that was dug up for this swamp-area, went. This would have made the treasure hiders effort a hell of a lot easier to use an existing natural cave system, than have to dig these deep extensive holes to bury a treasure. 

It would also make sense regarding those timberlogs-sections the first treasure-seekers found in that money-pit hole. Every ten feet they dug there was tight horizontal layers layers of timber logs in place, and it would make sense to put them there if one just filled up an existing hole that had spacious caverns at the bottom. Otherwise the soil would just keep filling up the cave, and also there would be natural settings of the soil over the years so a hole would be visible if the soil where let to just settle naturally - and they didn't want that.

Considering it would be quite an monumental task to dig these deep holes from scratch, it would be an much easier task to just fill in a natural made cave-system.

If there actually is a treasure down there, this would be my bet on how it all went down.

On last nights episode a lead cross was found via metal detecting. It had a resemblance to the engraved in stone cross at that French castle.